Two-Dimensional (PEA)2PbBr4 Perovskites Sensors for Highly Sensitive Ethanol Vapor Detection.

Two-dimensional (2D) perovskite have been widely researched for solar cells, light-emitting diodes, photodetectors because of their excellent environmental stability and optoelectronic properties in comparison to three-dimensional (3D) perovskite. In this study, we demonstrate the high response of 2D-(PEA)2PbBr4 perovskite of the horizontal vapor sensor was outstandingly more superior than 3D-MAPbBr3 perovskite. 2D transverse perovskite layer have the large surface-to-volume ratio and reactive surface, with the charge transfer mechanism, which was suitable for vapor sensing and trapping. Thus, 2D perovskite vapor sensors demonstrate the champion current response ratio R of 107.32 under the ethanol vapors, which was much faster than 3D perovskite (R = 2.92).

Effect of a Rubidium Chloride Carrier Confinement Layer on the Characteristics of CsPbBr3 Perovskite Light-Emitting Diodes.

This work describes the effect of a rubidium chloride (RbCl) interlayer in CsPbBr3 perovskite light-emitting diode (LED) structures. RbCl crystallites exhibited polyhedral structures and lattice parameters similar to those of CsPbBr3 perovskite crystallites. The lattice mismatch between the RbCl interlayer and CsPbBr3 active layer was only approximately 2%. The devices exhibited the best quality and performance when RbCl was used as the nucleation and carrier confinement layer. The crystallite sizes of CsPbBr3 with 0.2-, 0.5-, and 1-nm-thick RbCl bottom layers were 55.1, 65.4, and 55.1 nm, respectively. The full width at half maximum (FWHM) of the photoluminescence (PL) emission peak for CsPbBr3 with the RbCl bottom layer was 0.096 eV.

The Effects of Temperature on the Growth of a Lead-Free Perovskite-Like (CH3NH3)3Sb2Br9 Single Crystal for An MSM Photodetector Application.

We have fabricated a photodetector based on (CH3NH3)3Sb2Br9 (MA3Sb2Br9) lead-free perovskite-like single crystal, which plays an important role in the optoelectronic characteristics of the photodetector as a perovskite-like photosensitive layer. Here, MA3Sb2Br9 single crystals were synthesized by an inverse temperature crystallization process with a precursor solution at three different growth temperatures, 60 °C, 80 °C, and 100 °C. As a result, a MA3Sb2Br9 single crystal with an optimum growth temperature of 60 °C presented a low trap density of 2.63 × 1011 cm-3, a high charge carrier mobility of 0.75 cm2 V-1 s-1, and excellent crystal structure and optical absorption properties. This MA3Sb2Br9 perovskite-like photodetector displayed a low dark current of 8.09 × 10-9 A, high responsivity of 0.113 A W-1, and high detectivity of 4.32 × 1011 Jones.

Clinical features of tuberculosis and Bacillus Calmette-Guérin (BCG) -associated adverse effects in children: A 12-year study.

PURPOSE: To investigate the clinical feature of tuberculosis and BCG adverse effects in children and to examine whether delayed BCG vaccination changes the incidence of BCG osteomyelitis. METHODS: We analyzed patients younger than 18 years with tuberculosis or BCG-associated adverse effects from 2008 to 2019. We compared their clinical features, laboratory tests and outcomes. RESULTS: Totally 137 patients were collected, with 27% of pulmonary tuberculosis (PTB), 31% of extrapulmonary tuberculosis (EPTB) and 42% of BCG-associated adverse effects. The median age was older in PTB than EPTB group (17.1 vs 15.4 years; p = 0.015). More patients in EPTB group had fever than PTB group (55% vs 25%; p = 0.008). Compared with exclusively EPTB, more patients in EPTB plus PTB group had fever (78% vs 38%; p = 0.009), and had more systemic symptoms (67% vs 25%; p = 0.007), lower absolute lymphocyte count (1230 vs 1850/µL; p = 0.033), higher CRP level (5.62 vs 2.21 mg/dL; p = 0.024) and longer hospital stay (20 vs 11 days; p = 0.031). In BCG osteomyelitis group, the median time interval from vaccination to diagnosis was 16.4 months (IQR 15.0-20.2). Age at vaccination, either at birth or 5-8 month-old, did not affect the proportion of BCG osteomyelitis among children with BCG-associated adverse effects. CONCLUSION: Children with EPTB plus PTB had more fever, lower lymphocyte count and higher CRP. The median time interval from vaccination to diagnosis of BCG osteomyelitis was 16.4 months and the proportion of BCG osteomyelitis among children with BCG-associated adverse effects was not affected by delayed vaccination in this study.

Severe Mycoplasma pneumoniae pneumonia requiring intensive care in children, 2010-2019.

BACKGROUND/PURPOSE: Despite the high prevalence of Mycoplasma pneumoniae infections, reports on severe life-threatening M. pneumoniae pneumonia (MPP) in children are limited. METHODS: We retrospectively enrolled pediatric patients with PCR-positive MPP requiring ICU admission in a children's hospital in Taipei, Taiwan from Jun 2010 to October 2019. Clinical manifestations and laboratory data of severe MPP were analyzed. Macrolide susceptibility was determined by genotyping, and its relationship with clinical manifestations was also analyzed. RESULTS: Approximately 5% (34/658) children hospitalized for MPP required ICU admission. Compared with non-ICU cases (n = 291), ICU cases (n = 34) were associated with more underlying conditions, more pleural effusion, longer fever duration, longer hospital stay, the requirement of second-line antibiotic treatment, and delayed effective and second-line antibiotic treatment. Macrolide resistance was similar in ICU and non-ICU groups (53% vs 53%; p = 0.986). In severe MPP, patients requiring endotracheal intubation were associated with more septic shock, empyema, ARDS, prolonged fever after effective antibiotic treatment, delayed second-line and effective antibiotic treatment. In 18 of the 22 patients with pleural fluid analysis, the pleural effusion was alkaline (pH > 7.7) and lymphocyte-predominant. CONCLUSION: M. pneumoniae infection can cause severe life-threatening pneumonia in children. Delayed effective and second-line antibiotic treatments are associated with severe life-threatening MPP.

Clinical features and risk factors associated with bacteremia of nontyphoidal salmonellosis in pediatric patients, 2010-2018.

BACKGROUND/PURPOSE(S): This study aimed to investigate clinical features and antimicrobial susceptibility of inpatient children with nontyphoidal salmonellosis from 2010 to 2018. METHODS: We retrospectively collected pediatric patients with nontyphoidal Salmonella infection confirmed by positive cultures in a tertiary medical center in Taiwan from 2010 to 2018. Patients' characteristics, clinical manifestations, and laboratory data were collected. Serogroup category and antimicrobial susceptibility were also analyzed. RESULTS: Of total 569 isolates, ampicillin resistant rate was 53% in average, third-generation cephalosporin resistant rate was 6.7%, ciprofloxacin resistant rate was 9% and trimethoprim-sulfamethoxazole resistant rate was 30%. Compared to the resistant rates in 2010, the resistance rate of third generation cephalosporin was significantly higher (3.4% vs. 11%, p = 0.003) but that of ciprofloxacin was significantly lower (20% vs. 11%, p < 0.001) in 2018. Among 297 inpatients with nontyphoidal salmonellosis, Group D (38%) was the most common in the bacteremia patients whereas Group B (48%) was the most common in the non-bacteremia patients. Among 244 immunocompetent inpatients with community-acquired salmonellosis, the bacteremia patients had significantly longer fever duration and diarrhea duration before hospitalization (p < 0.001), and significant higher rate of anemia (p = 0.028) due to either thalassemia trait or prolonged disease course than the non-bacteremia patients. CONCLUSION: Third-generation cephalosporin was still the drug of choice for nontyphoidal Salmonella infection in children though the resistant rate increased progressively. Significant risk factors associated with bacteremia were longer fever and diarrhea duration and anemia due to either thalassemia trait or prolonged disease course in immunocompetent children.

Red Light-Emitting Diodes with All-Inorganic CsPbI3/TOPO Composite Nanowires Color Conversion Films.

This work presents a method for obtaining a color-converted red light source through a combination of a blue GaN light-emitting diode and a red fluorescent color conversion film of a perovskite CsPbI3/TOPO composite. High-quality CsPbI3 quantum dots (QDs) were prepared using the hot-injection method. The colloidal QD solutions were mixed with different ratios of trioctylphosphine oxide (TOPO) to form nanowires. The color conversion films prepared by the mixed ultraviolet resin and colloidal solutions were coated on blue LEDs. The optical and electrical properties of the devices were measured and analyzed at an injection current of 50 mA; it was observed that the strongest red light intensity was 93.1 cd/m2 and the external quantum efficiency was 5.7% at a wavelength of approximately 708 nm when CsPbI3/TOPO was 1:0.35.

Effects of Annealing on Characteristics of Cu2ZnSnSe4/CH3NH3PbI3/ZnS/IZO Nanostructures for Enhanced Photovoltaic Solar Cells.

This paper presents new photovoltaic solar cells with Cu2ZnSnSe4/CH3NH3PbI3(MAPbI3)/ZnS/IZO/Ag nanostructures on bi-layer Mo/FTO (fluorine-doped tin oxide) glasssubstrates. The hole-transporting layer, active absorber layer, electron-transporting layer, transparent-conductive oxide layer, and top electrode-metal contact layer, were made of Cu2ZnSnSe4, MAPbI3 perovskite, zincsulfide, indium-doped zinc oxide, and silver, respectively. The active absorber MAPbI3 perovskite film was deposited on Cu2ZnSnSe4 hole-transporting layer that has been annealed at different temperatures. TheseCu2ZnSnSe4 filmsexhibitedthe morphology with increased crystal grain sizesand reduced pinholes, following the increased annealing temperature. When the perovskitefilm thickness was designed at 700 nm, the Cu2ZnSnSe4 hole-transporting layer was 160 nm, and the IZO (indium-zinc oxide) at 100 nm, and annealed at 650 °C, the experimental results showed significant improvements in the solar cell characteristics. The open-circuit voltage was increased to 1.1 V, the short-circuit current was improved to 20.8 mA/cm2, and the device fill factor was elevated to 76.3%. In addition, the device power-conversion efficiency has been improved to 17.4%. The output power Pmax was as good as 1.74 mW and the device series-resistance was 17.1 Ω.

Study of Metal-Semiconductor-Metal CH3NH3PbBr3 Perovskite Photodetectors Prepared by Inverse Temperature Crystallization Method.

Numerous studies have addressed the use of perovskite materials for fabricating a wide range of optoelectronic devices. This study employs the deposition of an electron transport layer of C60 and an Ag electrode on CH3NH3PbBr3 perovskite crystals to complete a photodetector structure, which exhibits a metal-semiconductor-metal (MSM) type structure. First, CH3NH3PbBr3 perovskite crystals were grown by inverse temperature crystallization (ITC) in a pre-heated circulator oven. This oven was able to supply uniform heat for facilitating the growth of high-quality and large-area crystals. Second, the different growth temperatures for CH3NH3PbBr3 perovskite crystals were investigated. The electrical, optical, and morphological characteristics of the perovskite crystals were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible spectroscopy, and photoluminescence (PL). Finally, the CH3NH3PbBr3 perovskite crystals were observed to form a contact with the Ag/C60 as the photodetector, which revealed a responsivity of 24.5 A/W.

Effects of a quenching treatment on PCDD/F reduction in the bottom ash of a lab waste incinerator to save the energy and cost incurred from post-thermal treatment.

Bottom ash (BA) from incineration has been reused as a construction material for years. However, thermal treatments, which incur extra cost and higher energy demand, are essential to reduce/stabilize the polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in BA, which can be released from BA during the next startup and cause peak emissions. In this study, the bottom ash from a laboratory waste incinerator (LWI) was collected and quenched at various temperatures during three shutdown operations to determine the results of the gradual cooling process. The PCDD/F content in the BA was quantified using gas chromatography-mass spectrometry. The PCDD/Fs in BA was significantly lower (0.0239 ng WHO-TEQ g-1) after being quenched at >400 °C, which was only 1/300 of that in the sample gradually cooled to <200 °C (6.21 ng WHO-TEQ g-1). The PCDD/PCDF ratios were less than 1 in all of the samples, suggesting that de novo synthesis might be the predominant formation mechanism, and exponential relationships between the PCDD/F growth ratio and quenching temperature were found, with an r2 > 0.97. In other words, careful operation of the cooling process is an important PCDD/F inhibition strategy and effectively reduces the subsequent startup emissions. Interestingly, the extremely low PCDD/F levels in the BA after quenching were found to further save the cost of thermal treatment, reduce electricity use by 500 MWh, and lower fuel consumption by 27 kL of diesel, as well as reducing annual CO2e emissions by 351 tons in an LWI. This finding could be further applied to simultaneously control PCDD/F emissions, save post-treatment costs, and reduce the secondary pollutants in other incinerators.

A Novel AURKA Mutant-Induced Early-Onset Severe Hepatocarcinogenesis Greater than Wild-Type via Activating Different Pathways in Zebrafish.

Aurora A kinase (AURKA) is an important regulator in mitotic progression and is overexpressed frequently in human cancers, including hepatocellular carcinoma (HCC). Many AURKA mutations were identified in cancer patients. Overexpressing wild-type Aurka developed a low incidence of hepatic tumors after long latency in mice. However, none of the AURKA mutant animal models have ever been described. The mechanism of mutant AURKA-mediated hepatocarcinogenesis is still unclear. A novel AURKA mutation with a.a.352 Valine to Isoleucine (V352I) was identified from clinical specimens. By using liver-specific transgenic fish overexpressing both the mutant and wild-type AURKA, the AURKA(V352I)-induced hepatocarcinogenesis was earlier and much more severe than wild-type AURKA. Although an increase of the expression of lipogenic enzyme and lipogenic factor was observed in both AURKA(V352I) and AURKA(WT) transgenic fish, AURKA(V352I) has a greater probability to promote fibrosis at 3 months compared to AURKA(WT). Furthermore, the expression levels of cell cycle/proliferation markers were higher in the AURKA(V352I) mutant than AURKA(WT) in transgenic fish, implying that the AURKA(V352I) mutant may accelerate HCC progression. Moreover, we found that the AURKA(V352I) mutant activates AKT signaling and increases nuclear ß-catenin, but AURKA(WT) only activates membrane form ß-catenin, which may account for the differences. In this study, we provide a new insight, that the AURKA(V352I) mutation contributes to early onset hepatocarcinogenesis, possibly through activation of different pathways than AURKA(WT). This transgenic fish may serve as a drug-screening platform for potential precision medicine therapeutics.

Preparation and Characteristics of MAPbBr3 Perovskite Quantum Dots on NiOx Film and Application for High Transparent Solar Cells.

In this work, a MAPbBr3 quantum dot (QD-MAPbBr3) layer was prepared by a simple and rapid method. Octylammonium bromide (OABr) gives the MAPbBr3 better exciton binding energy, good surface morphology, and stability. To form a nanocrystalline thin film on indium tin oxide (ITO) glass, the QD-MAPbBr3 film was coated by a spin-coating method in a nitrogen-filled glove box and the NiOx film was used as an adhesive layer and hole transport layer. The highest transmittance of MAPbBr3 on NiOx/ITO glass was around 75% at 700 nm. This study also reported a high transparent and perovskite bulk-free ITO/NiOx/QD-MAPbBr3/C60/Ag solar cell where the NiOx, QD-MAPbBr3, and C60 were used as a hole transport layer, active layer, and electron transport layer, respectively.

Effect of Different CH3NH3PbI3 Morphologies on Photovoltaic Properties of Perovskite Solar Cells.

In this study, the perovskite layers were prepared by two-step wet process with different CH3NH3I (MAI) concentrations. The cell structure was glass/FTO/TiO2-mesoporous/CH3NH3PbI3 (MAPbI3)/spiro-OMeTAD/Ag. The MAPbI3 perovskite films were prepared using high and low MAI concentrations in a two-step process. The perovskite films were optimized at different spin coating speed and different annealing temperatures to enhance the power conversion efficiency (PCE) of perovskite solar cells. The PCE of the resulting device based on the different perovskite morphologies was discussed. The PCE of the best cell was up to 17.42%, open circuit voltage of 0.97 V, short current density of 24.06 mA/cm2, and fill factor of 0.747.

Expression of Neuroendocrine Factor VGF in Lung Cancer Cells Confers Resistance to EGFR Kinase Inhibitors and Triggers Epithelial-to-Mesenchymal Transition.

Mutations in EGFR drive tumor growth but render tumor cells sensitive to treatment with EGFR tyrosine kinase inhibitors (TKI). Phenotypic alteration in epithelial-to-mesenchymal transition (EMT) has been linked to the TKI resistance in lung adenocarcinoma. However, the mechanism underlying this resistance remains unclear. Here we report that high expression of a neuroendocrine factor termed VGF induces the transcription factor TWIST1 to facilitate TKI resistance, EMT, and cancer dissemination in a subset of lung adenocarcinoma cells. VGF silencing resensitized EGFR-mutated lung adenocarcinoma cells to TKI. Conversely, overexpression of VGF in sensitive cells conferred resistance to TKIs and induced EMT, increasing migratory and invasive behaviors. Correlation analysis revealed a significant association of VGF expression with advanced tumor grade and poor survival in patients with lung adenocarcinoma. In a mouse xenograft model of lung adenocarcinoma, suppressing VGF expression was sufficient to attenuate tumor growth. Overall, our findings show how VGF can confer TKI resistance and trigger EMT, suggesting its potential utility as a biomarker and therapeutic target in lung adenocarcinoma. Cancer Res; 77(11); 3013-26. ©2017 AACR.